[fix] Bignum comparison with Float in <=> and ==#9337
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headius merged 1 commit intojruby:jruby-10.0from Mar 28, 2026
Merged
[fix] Bignum comparison with Float in <=> and ==#9337headius merged 1 commit intojruby:jruby-10.0from
headius merged 1 commit intojruby:jruby-10.0from
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op_cmp converted the Bignum to double via big2dbl before comparing with the Float, losing precision for large values. For example, (2**64 + 1) <=> (2**64).to_f returned 0 instead of 1 because big2dbl(2**64 + 1) rounds to 2**64. op_equal had the same issue: (2**64 + 1) == (2**64).to_f returned true instead of false. Fix op_cmp to use the existing float_cmp method (rb_integer_float_cmp) which decomposes the float into integer and fractional parts and compares without precision loss. Add float_eq (rb_integer_float_eq) for op_equal using the same approach. Note: big_op (>, >=, <, <=) already used float_cmp correctly.
headius
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Looks good. Unsure if these specs are specific enough to stay in JRuby. Perhaps move some or all to ruby/spec.
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op_cmp converted the Bignum to double via big2dbl before comparing with the Float, losing precision for large values. For example,
(2**64 + 1) <=> (2**64).to_freturned0instead of1becausebig2dbl(2**64 + 1)rounds to2**64.op_equal had the same issue:
(2**64 + 1) == (2**64).to_freturnedtrueinstead offalse.Fix op_cmp to use the existing float_cmp method (rb_integer_float_cmp) which decomposes the float into integer and fractional parts and compares without precision loss. Add float_eq (rb_integer_float_eq) for op_equal using the same approach.
Note: big_op (>, >=, <, <=) already used float_cmp correctly.